Study to Evaluate Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of NTLA-2001 in Patients With Hereditary Transthyretin Amyloidosis With Polyneuropathy (ATTRv-PN) and Patients With Transthyretin Amyloidosis-Related Cardiomyopathy (ATTR-CM)

Polyneuropathy Inclusion Criteria: * Male and/or female participants 18 to 80 years of age inclusive, at the time of signing the informed consent * Diagnosis of polyneuropathy (PN) due to transthyretin (TTR) amyloidosis (ATTR) * Must have a body weight of at least 45 kilograms (kg) at Screening visit * Lack of access to approved treatments for ATTR and/or progression of hereditary transthyretin amyloidosis with polyneuropathy (ATTRv-PN) despite use of approved treatment for ATTRv-PN Polyneuropathy Exclusion Criteria: * Amyloidosis attributable to non-TTR protein, e.g., amyloid light-chain (AL) amyloidosis * Known leptomeningeal transthyretin amyloidosis * Use of any of the following TTR-directed therapy for ATTR within certain timeframe: 1. Patisiran 2. Inotersen 3. Vutrisiran 4. Tafamidis 5. Diflunisal 6. Doxycycline and/or tauroursodeoxycholic acid 7. Any other investigational agent for the treatment of ATTRv-PN: * Other protocol defined Inclusion/Exclusion criteria may apply Cardiomyopathy Inclusion Criteria (UK only): * Male and/or female participants 18 to 90 years of age inclusive, at the time of signing the informed consent * Diagnosis of transthyretin (ATTR) amyloidosis with cardiomyopathy, classified as hereditary ATTR amyloidosis with cardiomyopathy (ATTRv-CM) or wild type cardiomyopathy (ATTRwt-CM). * Must have a body weight of at least 45 kilograms (kg) at Screening visit * New York Heart Association (NYHA) Class I-III heart failure * At least 1 prior hospitalization for heart failure and/or clinical evidence of heart failure. * Able to complete ≥150 meters on the 6-minute walk test (6-MWT) during the Screening period. Cardiomyopathy Exclusion Criteria (UK only): * Amyloidosis attributable to non-TTR protein, e.g., amyloid light-chain (AL) amyloidosis * Known leptomeningeal transthyretin amyloidosis * Use of any of the following TTR-directed therapy for ATTR within certain timeframes: 1. Patisiran 2. Inotersen 3. Vutrisiran 4. Tafamidis 5. Diflunisal 6. Doxycycline and/or tauroursodeoxycholic acid 7. Investigational TTR stabilizer (e.g., AG-10) * Participants with heart failure that in the opinion of the investigator is caused by ischemic heart disease, hypertension, or uncorrected valvular disease and not primarily due to transthyretin amyloid cardiomyopathy. * Participants with a history of sustained ventricular tachycardia or aborted ventricular fibrillation or with a history of atrioventricular (AV) nodal or sinoatrial (SA) nodal dysfunction for which a pacemaker is indicated but will not be placed. Pacemaker or defibrillator placement, initiation of or change in anti-arrhythmic medication within 28 days prior to study drug administration. * Other protocol defined Inclusion/Exclusion criteria may apply